Telephone system



Dec. 10, 1929. w c s 1,738,624

TELEPHONE SYSTEM Filed Nov. 12, 1927 2 Sheets-Sheet 1 Imren m."

John Hicks Dec. 10, 1929. J. wlcKs TELEPHONE SYSTEM Filed Nov. 12, 1927 2 Sheets-Sheet 2 Im .ren 01- Juhn I/LIi/Jk 5' WW5 1T JOHN WICKS,

. device in automatic systems, may

densome and time consuming.

means, whereby a subscriber at I Fatented Dec. 10, 1929 01 OAK- PARK, ILLINOIS, ASSIGNOR TO PATENT OFFICE,

OEKANSAS CITY, MISSOURI, A CORPORATION OF DELAWARE irELErnonEsYsrEm Application filed November 12, 1927. Serial 1%. 232,734.. I

The present invention relates in general to telephone systems, and, is more particularly concerned with new and improved equipment for obtaining connections between a calling and a called line.

It sometimes occurs that a subscriber at a given station may have occasion to call certain otlierstations at frequent intervals. When this is the case, the delay incident to the operation in manual systems, or the labor occasioned by the operation of the calling prove bur- The object invention is to provide novel a special substation may extend connections by directive}? controlling serially related switches, and a ditional means enabling him to obtain connection with any one of a limited number of other stations by merel dialling a single digit, instead of a plurality of digits.

To accomplish this object, the special sub station is equipped with a regular calling device and with a code calling device. The first serves to establish connections in the usual manner by generating trains of imulses in order to directively operate serialy related switches in the exchange into connection with a desired called line, and the code calling device is used for calling a certain limited number of subscribers, by simply dialling one single predetermined digit instead of calling the digitsin accordance with the directory number.

of the present The exchange equipment which indi-- vidual to the speclal substation consists of a repeater associated with the usual line switch, and of various registers and sender switches. Then the regular calling device is operated, the series of impulses generated thereby will be transmitted, by the repeater, to the switch train as usual, without oper ating the register equipment. However, when the code ca ing device is actuated, a discriminating relay in the repeater immediately changes the circuits to direct the code series of impulses to the register switches, which are thus set in accordance with the desired code. The transmission of the trains of .impulsesnecessary for establishing the nEsEnvE HOLDING comrm,

connection takes place automatically by I means of the sender equipment associated with the register switches. Y The calling subscriber receives a signal during the transmission of each impulse train which indicates to him the numeric value of each digit transmitted to the serially related switches. Thus, the burden of dialling the whole series of digits is eliminated, and the invention represents therefore .an improvement which will be of service to subscribers who have occasion to call certaln other subscribers frequently.

The invention-is illustrated in the accompanyingtwo sheets of drawings, which show only equipment necessary for understanding the invention. Unessential details, and

known apparatus have been omitted in order tokeep the drawings and the description as simple as possible.

. ig. 1 shows a special substation A equipped with a regular calling device RC1) and with a'code calling device CCD. These.

two calling deyices are shown in the drawing separately, but are in reality combinedto one mechanical unit. Numeral 5 designates the switch hook of the substation which i is adapted to operate the contactsli and 7. Thereference numerals 8 and 9 denote the receiver and the transmitter, respectively;

reference numeral 16 designates the induc- 3 t1on coil; 14 and 15 indicate-the usual ringer v and the condenser, respectively.-

The repeater consists of a number of re lays shown in Fig. 1, whose function will be described in detail later on. At this point of the description, only the function of relay '70 will be intimated. This relay is a differential relay, and, as is apparent from the drawing, is normally in series with the line conductors 1 and 2. When the regular calling device is operated this relay is in a loop circuit with the calling substation and does not operate. However, when the code calling device is actuated ground will be connected to the line conductor 1, which unbalances the relay 17. The relay operates and changes the circuits of the repeater in order to permit the transmission of the code series to the register switches shown in Fig.

Referring now to Fig. 2, the reference numerals 54 and 64 indicate two reglster switches, each having five wipers. In response to the operation of the code calling device these two register switches will be op erated simultaneously, and will set their wi rs on bank contacts determined by the cod transmitted from the calling substatlon. structurally, these two switches are ordinary rotary switches of known construction, each provided with a twenty-five point bank. The code dial, it may be mentioned, is a twentyfive point dial, which means that this dial is capable of transmitting a maximum of twenty-five impulses. It will, therefore, be apparent that twenty-five different codes can be rovided for a specially equipped substation. gt will also be understood that the two register switches 54 and 64 could be combined in one having a set of nine wipers. Two switches instead of one, have been employed, however, in order to permit the use of standard equipment.

Each set of bank contacts of the register switches 54 and 64 is wired to a cross connecting terminal block designated 200. From this terminal block, cross connections are provided to bank contacts of an impulse control switch designated 174. The function of this switch will be apparent from the progressing description.

The reference numeral 184 designates a digit-sequence control switch. As will be mted out more particularly later on, the

rst digit necessary for establishing the desired connection corresponding to a dialled code, will be transmitted with the dig1t seuence control switch 184 in the position s own in the drawing. The number of impulses of each digit is determined by the impulse control switch 174. When the first digit is transmitted the impulse control switch 174 releases, while the digit sequence control switch 184 steps from the position 1 to position 2. The sequence of operation, broadly stated, is the same as far as the switches 174 and 184 are concerned, until all the digits necessary for calling the desired subscriber are transmitted by the equipment. The detailed description of the operation of the invention will now be presented.

It will be assumed first that the subscribor at the substation A desires to establish a connection with a called subscriber by dialling the directory number. The regular callin device will be used for this purpose.

en the subscriber removes his receiver from the switch hook, an obvious loop circuit will be closed at the switch hook contacts 6 and 7-, which extends from the line conductor 1, armature 82 and its resting contact, lower left hand winding 74 of the repeating coil and the lower winding of the differential relay 70 to ground, and from the line conductor 2, over the armature 81 and its resting contact, upper left hand winding 72 of the repeating coil, upper winding of relay 70 and winding of relay 10 to battery. Relay 10 operates inthis circuit, while the relay 70 does not operate on account of being differential. Relay 10 operates its armature 11, thereby closin a circuit for the slow acting relay 120, and the latter operates its armature 122 thereby providing a circuit for the relay 20.- Relay 10, upon operating closes its armature 13 and the relay 20, upon operatin actuates 1ts armature 21. A loop circuit is now provided for the operation of the line switch (not shown) which may be traced as follows: conductor 3, armature 61 and the contacts 31 and 33 of a pendulum interrupter in parallel, armature 21 and its make contact, upper right hand winding of the repeating coil, armature 13 and its make contact, lower right hand winding 7 5 of the repeating coil, and conductor 4 back to the lineswitch. No lineswitch circuit has been shown since any known lineswitch can be used in connection with this repeater circuit. The lineswitch operates in the usual manner to select an idle trunk line terminating in a selector switch.

When the subscriber at substation A operates the regular calling device RCD, the circuit of the line relay 10 of the repeater will be interrupted in accordance with the digit from which the dial has been operated. The line relay 10, accordingly, deenergizes a number of times in succession and at each deenergization, it opens the loop circuit extending to the exchange at armature 13, thereby giving the necessary impulses for the actuation of the selector switch selecter by the line switch. Relay 120 is 'slowacting, and does not follow the interruptions although its circuit is being opened at armature 11 of relay 1Q. Accordingly, armature 122 of relay 120 Wlll remain in operated position thereby-holding the relay 2O energized during the interruptions of theline relay 10. Upon the first deenergization of the line relay 10, a circuit will be closed for the slow acting relay 40, which may be traced from ground, armature 11 and its resting contact, make contact and armature 23, resting contact and armature 113, winding of the slow acting relay 40 to battery. Relay 40, being a slow acting relay, will also remain energized during the impulse operation of the line relay 10, and, at its armature 42 closes a shunt around the upper right hand winding 73 of the repeating coil in order to improve the impulsing circuit.

The subscriber at substation A transmits in this manner all the digits necessary for extending a connection. It will be understood that' each digit operates one of a train of switches by which the connection is to be extended. The last digit dialled at the substation A operates a connector into engagewith a desired party by means of using the scriber A answer eration takes place in the usual manner, and,

when the called party replies, the connection will be completed and the two subscribers can engage in conversation,

It will be assumed next that the subscriber shown at A in Fig. 1 is desired connector switch having access to thissubstation will seize theline conductors 3 and 4, and ringing current will be transmitted from 'the connector in order to ring the bell 14 of the substation A. The ringing current may be traced over' the conductors 3 and 4 by way of relay 100, the condenser 102 and the restg contact and armature 21. Relay 100 responds to the ringing current and operates its armature 1-01. A circuit is closed thereby for the relay 80, from battery, winding of relay 80, armature 101 and its make contact, resting contact and armature 12 to ground. Relay SOenergizes and operates its armatures 81 and 82, connecting the line conductors 1 and 2 in parallel to the ringing current which traverses the relay 100. The subscribers bell 14 which is bridged across the line conductors is thereby operated. Shouldthe subscriber at substation A reply. during a ringing period, the loop circuit over the substation A which is provided upon the removal of the receiver from the switch hook, causes the operation of a ring-cut-ofi relay in the connector which disconnects the ringing current from the line conductors 3 and 4. However, should the subthe-call during a pause in the ringing, the line relay will be operated in the line circuit, followed by the operation of relays 120'and 2Q. lVhen relay operates its armature 21, it disconnects the relay 100 and closes 'the loop circuit extending to the connector, which circuit includes the right hand repeating coil windings 73 and 75 which are at this moment connected together by way of armature 13 of the line relay 10. The ring-cut-ofl' relay in the connector energizes over this loop circuit, and disconnects the ringing current. v

. The operations as described above do not difier materially from the operations of known circuits, although the detailed arrangement may be somewhat different from the usual. The description has been presented, however, in order to furnish a complete explanation of all the operations involved It will be assumed next that the subscriber at substation A desires to make connection code calling device CCD. It will further be assumed that the wanted subscribers number is 4150 and that the corresponding code numher is number 1. Accordingly, the calling subscriber A will rotate the code callingdevice CCD from numeral 1 and will thereby transmit one impulse to the register switches 54 and 64 shown in Fig. 2. The switches will operate simultaneously in accordance with the tacts in their respective banks.

in a call. A'

single impulse and will advance their wipers into engagement with the first sets of-"on- These sets of contacts are indicated by reference numerals 1. After the register switches 54 and 64 are thus set, the complete digits 4, 1, 5, and 0 will be transmitted by the sender e uipment in order to operate the serially re ated exchange switches into connection with the des red line denoted by the code. These operations are as follows: i

When the subscriber at substation A removes the receiver from the switch hook a. loop circuit will be provided as in the case already described, which'includes the line relay 10 in series with the upper winding of the differential relay 17 over the line conductor 2, the loop of substation A, line conductor 1, and to ground over the lower winding of the differential relay 7 O. The line relay 1O operates as before, and closes the circuit for relay 120 at its armature 11. Relay 12 0 closes it's armature 122, thereby completing a circuit for relay 20. So far, the operations described are the same as those described in connection with the previous call. The difference in the operation appears when the subscriber operates his code calling device instead of the regular calling device.

The code calling device, it will be seen, has a contact 26, in addition to the usual contacts for shunting the receiver and transmitter and in addition to the impulse contacts 27. This auxiliary contact 26 connects ground to the line conductor 1 while the dial is operated. The lower winding of the difierential relay 7 0 will be shunted thereby, which unbalancesthe relay and causes the same to operate. Relay 70 closes its armature 71 completing a circuit for the relay tery, winding of relay 160, make contact and armature 71, make contact and armature 24, resting contact and armature 92 to ground. At armatures 161 and 163 the relay 160 disconnects the rivate wipers 57 and 67 of the register switc es 54 and 64 from the winding of therotary magnets and 65. The circuits of the rotary magnets which are interrupted at this moment at the armatures 161 and 163 are provided for returning the two register switches to normal position after a call has been set up. This operation will be described later. At its armatures 166 and 168, the relay 160 prepares circuits for the operation of the rotary magnets 55 and 65 respectively; at armature 164 a circuit is prepared for relay 110; at armature 167 the relay 160 provides a holding circuit for itself in parallel to the armature 71; at armature 162, the impedance 169 is bridged across the conductors 3 and 4 for a purpose which will be explained later on; and at armature 165 a circuit is closed for the operation of the pendulum interrupter 30 from ground, armature and make contact 165, winding of the interrupter 30,

normally closed contact controlled by armature 142, and resistance 52 to battery.

The above 0 erations take place in the moment the su scriber at substation A rotates the calling device CCD 011 normal, there by closing the contact 26. This contact will of course remain closed as long as the dial is 011 normal. An impulse is now transmitted to the line relay 10 by the impulse springs 27, which will be opened for a short period when the dial returns to normal. Relay 10, upon deenergizing, opens the circuit of relay 120, and closes at the same time the circuit for the rotary magnet 55 of-the register switch 54 from ground, armature 11 and its resting contact, make contact and armature 23, resting contact and armature 113, armature 166 and its make contact, conductor 55', and winding of the rotary magnet 55 to battery. A circuit parallel to the above may be traced from armature 113, winding of the slow acting relay 40 to battery. The slow acting rerelay 40 will therefore energize during impulsing, and the register switch 54 wi. receive one impulse, and will advance its wipers into engagement with the first bank contacts which are shown connected to the crossconnecting block 200. The wiper 57, which is a private wiper will be advanced into engagement with the lowermost contact of the contact set, which is multipled with similar contacts of all sets in the contact bank with the exclusion of the twenty-fifth set. These multipled contacts are connected to ground. The utility of this provision will be described in connection with the release operation of the register switch. Relay 10, upon deenergizing, also retracts its armature 12, thereby transmitting an impulse to the rotary magnet of the register switch 64 as follows: ground, armature 12 and its resting contact, armature 168 and its make contact, resting contact and armature 114, conductor 65, and winding of the rotary magnet 65 to battery. The register switch 64 similar to the register switch 54 will advance its wipers into engagement with the first set of bank contacts which are wired to the cross connecting terminal block 200, while its wiper 67 will be advanced into connection with the first contact which is multiplied with all similar contacts throughout the entire contact bank, with the exception of the twenty-fifth similar to the corresponding contacts in the contact bank of the register switch 54.

Relay 40, it will be remembered, was energized at the first deenergization of the line relay 10 in response to the impulse transmitted by the code dial. Upon operating, the relay 4O closed its armature 41 thereby connecting ground from armature 164 to the middle pointof the windings of relay 110.

' This relay is a two-step relay, and, in response to the energization of its lower winding in the above circuit, closes only its armatime 111, thereby connectin its upper winding by way of conductor 6 to the private wiper 67 of the register switch 64. Since the be completed including both windings of the relay by way of the private wiper 67, conductor 67 and armature 111 and its make contact. The relay 110, therefore operates fully, closing its remaining armatures, and hol ing itself energized over its armature 111 to ground connected by the private wiper 67 of the register switch 64.

At its armature 112, the relay 110 closes a circuit for the operation of rela which may be traced from battery, win ing of relay 130, resting contact and armature 173, make contact and armature 112, make contacts and armature 165 to ground. A branch circuit may be traced from the make contacts of armature 112 over conductor 185' to the wiper 185 of the digit sequence control switch 184. Viper 185 is therefore connected to ground. At its armature 113, the relay 110 opens the circuit of relay 40 and of the rotary magnet 55; and at armature 114 it opens the circuit of the rotary magnet 65 of the register switch. Relay 110 obviously will remain energized over both of its windings and its armature 11.1 as long as the private wiper 67 is in en gagement with a grounded contact in the private bank. The deenergizat-ion of relay 40 responsive to the openin of its circuit at armature 113 causes the isconnection of the original circuit for the lower winding of relay 110 at armature41.

It will be remembered that relay energized immediately upon the operation of relay 70 in response to the subscriber at substation A actuating the code calling device. This relay will hold itself energized in a circuit including its own armature 167 and the armature 24 to ground provided at armature 92. When relay 160 energized, it completed a circuit at armature for the operation of the interrupter 30. This interrupter is provided with a vibrating pendulum armature designated 32 which is efi'ective to close a contact,

to short circuit the winding 30 of the interrupter to cause its deenergization. Thus the interrupter 30 will control its own circuit in accordance with the swinging of the pendulum. This interrupter is subsequently used, as will be explained later, for transmittin impulsesv to the various seriallyi relate switches. Its energization takes place immediately upon the subscriber operating the code dial thereby causing the energizat-ion of relay 160, that is, its energization takes place previous to its use. This is necessary in order to allow the pendulum 32 to gain the required speed and to deliver about ten impulses per second. Whenever the Winding 30 of the pendulum interrupter deenergizes, the penduand is closed as relay 60 has not yet been op-.

l erated. The interrupter 30 operates, therefore, idle. while the dial "rotates back to deliver the impulses of the code series in order.

to operate the register switches 54 and 64.

The mechanism is now ready to transmit the four digits comprising the numerals 4, 1, 5, 0, in suctession to the various switches. This operation will now be described.

Relay 130 is operated responsive to the energization of relay 110, and closes its armature 131, completing a circuit for the relay 140 from battery, winding of relay 140, armature 172, armature 131 and its make contact to ground. -Relay 140 operates its armature 141, completing thereby a circuit fromground at armature 122 to the middle point of relay 60 as follows: battery, lower winding of relay 60, resting contact and armature 62, resting contact and'armature 51, make contact and armature 141, resting contact and arma ture 171, make contact and armture 122 to ground. Relay 60, similar to relay 110, is a "two-step relay, and, in response to the energization of its lower winding attracts only its armature 63, thereby preparing a circuit including both of its windings. At the present moment, it will be seen that the upper winding of relay 60 is short circuited by way of armatures 63, 141, 51, and 62. Armature 61 of relay 60 is still in resting position as shown in the drawing, shunting the'impulse springs 31 and 33 of the interrupter 30 so that at the present time no interruptions in the loop circuit to the selector switch are transmitted.

Relay 140 also closes its armature 142, thereby substituting the circuit over the re* sistance 52, by a circuitincluding the winding of relay 50. This relay does not energize in series with the winding 30 of the pendulum interrupter. However, whenever the pendulum 32 is ,efi'ective to short circuit and to deenergize thereby the winding 30, relay will operate. Assuming now that the pendulum armature 32 is in effective position, having short circuited the winding 30, the current -traversing the winding of relay 50 will be sufficient to energize this relay.

Relay 50 opcrates its armature 51, opening thereby the short circuit around the upper winding of relay 60 and permitting this relay to energize fully over both windings. Armature 61 of relay 60 is thereby opened to remove the shunt around the impulse springs 31 and 32. The pendulum interrupter 30 which is at this moment deenergizing releases the pendulum armature 32, which opens the impulse springs 31 and 33 to transmit an impulse over the conductors a and 4 to the selector teach-aka into' use by the lineswitch. When the pendulum armature ,32 opens the short circuit around the winding 30, the resistance of this winding is again inserted in the circuit of relay 50 and this relaydeenergizes. At its armature 51, the relay 50 closes at this time a circuit. for the operation of the rotary magnet 177 of the impulse control switch 174. This circuit may be traced from battery, r0-

tary magnet -177, conductor 177, armature- 62, resting contact and armature 51, and a-rmatures 141, 171, and122 to ground. The wiper 175 of the impulse control switch is thereby advanced into engagement with the first bank contact.

Following the connections shown in Fig. 2, it will be seen that the contact 1 with which the wiper 175 is now in engagement, is crossconnected at the terminal block 200, to a contact in the bank of the register switch 64 which is engaged by a wiper 0'9. This wiper is connected to the contact 2 of the digit sequence control switch 184. The wiper 17 5 is connected to the winding of relay 170 over the conductor 175. No circuit is closed at the present time for the operation of relay 170, since the digit sequence control switch 184 has not yet moved out of the first position.

Due to the opening of the short circuit around the winding 30 of the pendulum interrupter at the moment the pendulum 32 swings back and opens the contacts 31 and 33 the winding 30 is again energized to attract the pendulum 32. When this takes place, relay 50 is again, as before, energized to open its armature 51 interrupting thereby the circuit of the rotary magnet 177. When the pendulum 32 is sufliciently attracted to close the short circuit around the winding 30, this winding is again deenergized, releases the,

pendulum 32 which again swings back to separate spring 33 from spring 31, thereby sending an impulse to the selector switch. This action of course causes the inclusion of the winding 30 in series with relay 50 which deenergizes, closing its armature 51 in the same manner as described above, and ain closing a circuit for the transmission 0 an impulse to the rotary magnet 177 over the path traced above. Thus, whenever an impulse is delivered to the selector switch by interrupting the impulse springs 31 and 33, an impulse is also delivered to the rotary magnet 177 of the impulse control switch 174. This interaction of relay 50 which delivers impulses to the rotary magnet 177 and of the interrupter 30 which delivers corresponding impulses to the selector, continues until the wiper 17 5 of the impulse control switch encounters agrounded contact completing thereby a circuit'forthe relay 170.

Wiper 185 of the digit sequence control switch 184 is in engagement with the first bank contact, that is, the switch 184 is in the to ground.

sition in which the apparatus delivers the rst digit of the selector switch selected by the line switch. It will be remembered that the wiper 185 is connected to ground by way of armatures 112 and 165. Position 1 of the digit sequence control switch'184 is connected to the w1per68of the register switch 64, which is in engagement with the first bank contact. This bank contact is again connected to the cross-connection terminal block 200, and from there, a cross connection may be traced to the fourth contact in the bank accessible to wi er 175 of the impulse control switch 174. he wiper 175 will therefore encounter ground at the fourth bank contact and a circuit will be closed for the operation of relay 17 0 which may be traced from wiper 17 5, conductor 17 5', winding of slow acting relay 170 to battery. Relay 170 energizes and disconnects at the resting contact of its armature 172 the relay 140, at the same time providing a holdingcircuit for itself at the make contact of this armature, which circuit extends to ground over the oil-normal contact 178 of the impulse control switch. At the resting contact of the armature 171, the relay 170 opens the circuit for the relay 60; at the make contact of this armature a circuit is closed for the energization of the rotary magnet 186 of the digit sequence control switch 184, which ma be traced from battery, magnet 186, con uctor 186', make contact and armature 122 to ground. The digit sequence control switch 184 takes therefore one step and advances the wiper 185 into e'ngagement 'with the second bank contact, romoving thereby ground from the first bank contact and connecting it to the second bank contact. A circuit is now completed for the release magnet of the impulse control'switch 174 which may be traced from battery, release magnet 176, conductor 176, armature 22 and its make contact, make contact and armature 171, make contact and armature 122 Thus, the impulse control switch 114 is restored to normal position while the digit sequence control switch 184 is advanced from position 1 to position 2.

The first digit required for establishing the desired connection and consisting of four impulses has now been transmitted. Relay 60 is at this moment deenergized, having closed its armature 61. The impulse.v springs 31 and 33 are thereby shunted to prevent further sending of impulses. Relay 140 has been deenergized responsive to the operation of rela 170 which operated its armature 172. There ore, armature 142 is in the position shown in the drawing, having disconnected the relay 50 from the circuit of the interrupter 30 and substituted the original circuit including the resistance 52. The result of this operation is simply to continue the operation of the pendulum interrupter 30 but to deenergize relay 50, and to restore it to its ..original position with respect'to the impulse interruper. Relay 60 being also deenergized, it will be seen that the circuits are in the same position as before the transmission of the first digit.

The operations will now be repeated in the same sequence and in the same manner in order to transmit the second di it which consists of one impulse. Upon t c release of the impulse control switch 174, the relay 170 will deenergize since its original energizin circuit is open at the -wiper 17 5, and its ho ding circuit is now opened at the 011- normal springs 178. Relay 130 which is a slow acting relay was held energized over armature 173 and provided at armature 131 a parallel ground to the ground circuit of the closed off-normal contact 17 8. Relay 130, however, was deenergized upon the operation of relay 170. Therefore, there is no possibility for the'rela 170 to remain energized and this relay eenergizes, releasing its armature 172 and connecting thereby the relay 140 in circuit with the armature 131. At armature 173 the circuit for 130 is again closed and this relay energizes completing the circuit for relay 140. At armature 171 the circuit of the rotary magnet 186 of the digit sequence control switch 184 is opened and the original circuit for the energization of relay 60 and for the subsequent operation of the rotary magnet 177 of the impulse controlled switch 174 is closed. When relay '140 energizes, following the energization of relay 130, it completes again a circuit for the lower winding of relay 60 which attracts its armature 63 and prepares a circuit including its upper winding in series with the lower winding. This latter circuit will be effective upon the operation of relay 51 which removes the short circuit around the upper winding of relay 60 as was described previously. At armature 142, the relay 50 is again connected in series with the pendulum interrupter 30 in substitution of the circuit including resistance 52. When the pendulum interrupter 3O attracts its armature 32 to short circuit its own winding, the relay 50 will energize opening its armature 51 and thereby removing the short circuit around the upper winding of relay 60. This relay therefore energizes fully and attracts its remaining armature as in the previous case, removing the short circuit around the imulse springs 31 and 33 so that the pendulum lnterrupter 30 in releasing its armature 32 can open the springs 31 and 33 to transmit one impulse to the selector switch. When this occurs, the winding 30 of the pendulum interrupter is in series with the relay 50 and since relay 50 cannot remain operated in series with the winding 30, it deenergizes, restoring its armature 51 to the position shown in the drawing, and completing therecircuit includes thearmatures 122, 171, 141, 51, 62, and the conductor 17 7'. The impulse control switch 174 therefore moves its wiper 175 into engagement with its first bank contact. Tracing the connection from this bank contact it will be seen thata cross-connection is provided to the bank contact engaged by wiper 69 of the register switch 64 which is connected to the second bank contact accessible to the wiper 185 of the digit se-' I quence control switch 184. Since wiper 185,

it will be remembered, is connected to ground,

and the wiper 175 ofswitch 174 is connected to battery over the winding of relay 170, it

will be seen that a circuit is again provided for the operation of relay 170, which causes the energization of this relay. The result of this is again, as already'described in detail, the release of the impulse controlled switch 174 andthe simultaneous advance of the digit sequence control switch 184. The relays 60 and will again be disconnected, relay by closing its armature 6 1 preventing further transmission of impulses. v i

. The remaining digits will be transmitted in precisely the same manner described above in connection with the transmission of the first and second digit, A detailed explanation will therefore be omitted.

The digit sequence control switch 184 will advance to the fifth position after the fourth digit has been transmitted. In this position, the entire equipment is in readiness to transmit a further digit. However, in the present case only four digits are necessary in order to establish the desired connection, and, since these four digits have been transmitted, the register and sender equipment can be released. The release can be accom plished upon the termination of the trans mission of any digit. In the present case the release is desired upon the termination of the fourth digit, and, in order to accomplish it, a cross connection is provided in the terminal block 200, which is designated 201' and which causes the release of the equipment as follows:

It will be remembered that wiper 185 of the digit sequence control switch 184 is con; nected to ground by way of the conductor 185, and armatures 112, and 165. Upon the termination of the transmission of the fourth digit the wiper 185 is advanced to engage the fifth bank contact. This contact is connected to wiper 58 of the register switch 54 whichis in engagement with the bank contact cross connected to.conductor 121' by means of the cross connection 201. Following the conductor 121 it will be seen that this conductor terminates in the winding of relay 90 shown inFig. 1. When the wiper 185 of the switch 184 is advanced to the fifth position, a circuit will therefore be closed for the operation of relay 90. This relay operates,

an'd'opens at its armature 92 the circuit of relay 160, at the same time connecting ground to conductor 187 which terminates in the release magnet 187 of'the switch 184. Therefore, the digit sequence controlled switch 184 releases. At its armature 91, the relay 90 provides a holding circuit for itselfto conductor 95 which terminates in the off-normal contacts 95 operated by theswitch 184. Relay 90 will therefore remain operated while; the switch 184 releases. l I

It will be seen that the ninth bank contact accessible to wiper 185 is also connected to the stop conductor 121. This serves the purpose of releasing the equipment in case it is desired to transmit eight digits. In this case, the cross connection 201 is, of course, omitted. The maximum number of digits which can be transmitted is theerfore eight digits. The explanation of the release operations will be continued now.

Relay 160, upon deenergiz-ing, closes its armatures 161 and 163 completing circuits for the rotary magnets 55 and 66 of the register switches 54 and 64, respectively. The circuit for the rotary magnet 55 may be traced from ground connected to contacts 1 to 24, wiper 57, conductor 57 armature 161, conductor 56', interrupter springs 56 of the rotary magnet'55, and the winding of the rotary magnet to battery. This magnet therefore operates and interrupts its own circuit at interrupter springs 56 as long as the wiper 57 encounters ground in advancing over the bank contacts. When wiper 57 reaches the 25th bank contact it will not encounter ground andthe rotary magnet 55 will cease to operate. The register switch 54 is therefore restored to normaLposition.

The restoring circuit for the register switch 64, upon the release of relay 160, may be traced from ground connection to the multipled private contacts of switch 64, wiper 67, conductor 67, armature 163, conductor 66',

interrupter springs 66 controlled by the rotary magnet 65, and the winding of the retarymagnet to battery. The rotary magnet 65, similar to the rotary magnet 55, will interrupt its own circuit at spring 66 and will continue to rotate as long as the private wiper 67 encounters ground on one of the private contacts 1 to 24.- When it reaches the 25th contact, no ground will be encountered andthe switch will stop to operate.

The register switches 54 and 64 and the digit sequence control switch 184 are therefore restored to normal, while the -impulse control switch 17 4 was restored to normal position upon the termination of the transmission of the fourth digit.

Relay 160, upon deenergizing, also opens its armature 167, thereby interrupting its own holding circuit; at armature 165, ground is disconnected from the winding of the pendulum interrupter which ceases to operate;

and at armatures 166 and 168 the original circuits for the rotary magnets 55 and of the register switches are opened; at armature 164 ground is disconnected from the armature 41, which is of no con ue nce at the present time since the relay 40 is. in deenergized position; at armature 162 the 1m edance 169, which, during the operation 0 the sender equipment is connected in bridge of the conductors 3 and 4, is disconnected. The par ose of this impedance 169 will now be ex ained.

The various digits to the serially related switches are transmitted, as will be remembered, over the following circuit: line conductor 3, impulse springs 31 and 33, armature 162 and its make contact, impedance 169, and the conductor 4. The impedance 169 is therefore bridged across the line conductor in parallel with the two right hand windings 73 and 75 of the repeating coil, since the relay 10 and the relay 20 are energized, having operated their armatures 13 and 21, respectively, and connected the right hand windings of the repeating coil in the above circuit. Whenever the above loop circuit to the switch in question is interrupted by the impulse springs 31 and 33, the calling subscriber will receive a slight click in his receiver due tothe right hand repeater windings 73 and 75 being in inductive relation to the left hand windings 72 and 74. The calling subscriber receives this series of clicks corresponding to the series of impulses transmitted by the impulse contacts 31 and 33, which serves as a signal to him denoting the digits which are transmitted.

The above invention has been described in connection with a particular system. However, it will be apparent that the invention lends itself to modifications of various kinds, and it will therefore be understood that applicant does not desire to be limited in the use of the invention to the particular structure shown in the drawings. What is considered new and is desired to have protected by Let ters Patent will be pointed out specifically in the following claims:

What is claimed is:

1. In a telephone s stem, a calling line provided with a first an a second calling device, a plurality of switches accessible to said line andsuccessively responsive to said first calling device for directively extending a connection to a called line under control of said calling line, a register mechanism at the exchange.

stem a calling line provided with a st an a second calling device,

a plurality of seriall related switches accessible to said line an successively responsive to said first callin device for directively extending a connection to a called line under control of said callin line, a register mechanism individual to sald calling line, means in said mechanism including a pluralty of switches directively and simultaneously responsive to a single operation of said second calling device, and means controlled by the setting of said switches and subsequently operable for automatically operating said serially related switches to establish connection with a called line.

3. In a telephone system, a calling line provided with a first and a second impulse transmitting device, an impulse repeater and register mechanism individual to said line, a plurality of switches accessible to said repeater, means 1n sa1d repeater responsive to said first device for successively transmitting trains of impulses to said switches for directively extendin a connection to a called line under contro of said calling line, means in said repeater for transmittin a. single train of impulses generated at sai second device to said register mechanism, and automatic means for su sequently transmitting a plurality of trains of impulses to said switches to establish connection with a called line under control of said mechanism.

4. In a telephone system, a calling line provided with a first and a second impulse trans mitting device, an impulse repeater and register mechanism individual to said line, a plurality of serially related switches accessible to said repeater, means in said repeater responsive to the operation of said first device for successively transmitting trains of impulses to said switches for directively extending a connection to a called line under control of said calling line, a plurality of switches in said register, means in said repeater for simultaneously transmitting a single train of impulses generated at said second device to said switches in said register, and automatic means controlled by the setting of said switches for subsequently transmitting a plurality of trains of impulses to said serially related switches to establish connection with a called line.

5. In a telephone system, a calling line, register mechanism individual to said line, switches, means for operating said switches successively byseries of impulses generated at said calling line for directively extending a connection to a called line, and alternative means for extending a connection to said or to another called line, including means in said register responsive to a single series of impulses from said calling line for determining the number of digits and the numeric value of each digit, and automatic means for subsequently transmitting said digits to said switches.

6. Ina telephone system, a calling line,

register mechanism individual to said line,

serially related switches,means for operating said switches successively by series of impulse trains generated at said calling line for directively extending a connection to a called line, and alternative means for extending a connection to said or to another called line, including a plurality of switches in said register responsive to a single series of impulses from said calling line for determining the number of digits and the numeric value of each digit, and automatic means controlled by the setting of said register switches for subsequently transmitting said digits to said serially related switches.

7. In a telephone system, a calling station, a plurality of switches, a code registering mechanism individual to said station, means for settin said switches directly under control of said station without actuating said mechanism, for extending a connection to a called station, means for setting said mechanism by a single code series of impulses under control of said calling station, without actuating said switches, and automatic means in said mechanism for subsequently transmitting a plurality of series of impulses to said switches for extending the connection denoted by said code series. a

8. In a telephone system, a calling station, a plurality of serially related switches, a code mechanism individual to said station and in-- cluding a plurality of register switches and a plurality of sender switches, means for setting said serially related switches directively under control of said station without actuating said mechanism, for directively extending a connection to a called station, means for setting said register switches by a single code series of impulses under control of said calling station without actuating said serially related switches, and automatic means for subsequently operating said sender switches to transmita plurality of series of impulses to said serially related switches for extending the connection denoted by said code series.

9. In a telephone system, a calling station, a repeater and code registering mechanism individual to said station, a plurality of serially related switches, an impulse device at said station, means for operating said impulse device to transmit a plurality of trains of impulses to said repeater, means in said repeater for transmitting said trains to said serially related switches for directly extending a connection to a called station under control of said call ing station,means for operating said impulse device to transmit a single code series of impulses to said repeater, discriminating means in said repeater responsive thereto, means controlled by said discriminating means for transmitting said code series to said register mechanism without actuating said serially related switches, andautomatic means subsequently operable for transmitting a plurality oftrains of impulses to said serially related switches toestablish a connection to a called line denoted by said code seriesL Y 1 10. In a telephone system, a calling station, a repeater and code registeringlmechanism individual to said station, a plurality of serially related switches, an impulse device atsaid station, means for operating said impulse device to transmit a plurality of trains of impulses to said repeater, means in said repeater for transmitting said trains of impulses to said serially related switches for directly extending a connection to a called stat1on under control of said calling station, means for operating said impulse device to transmit a single code series of impulses to said repeater, discriminating means in said repeater responsive thereto, means controlled by sald discrlminating means for transmitting said code series to said register mechanism without actuating said serially related switches, automatic means subsequently operable for transmitting a plurality of trains of impulses to said serially related switches to extend a connection to a called line denoted by said code series, and means for transmitting a signal to said calling station etl'ective during the transmission of said trains of impulses and denoting the number of impulses of each train.

11. In a'telephone system, a calling station, a code registering and impulse sending mechanism individual to said station, a plurality of serially related switches, an impulse device at said station, means for operating said impulse device to transmit trains of impulses to said serially related switches for directively extending a connection to a called station under control of said calling station, means for operating said impulse device to transmit a code series of impulses to said register mechanism without actuating said serially related switches, and automatic means including said impulse sending mechanism operable subsequently for actuating said serially related switches 'to extend a connecti'on to a called station denoted by said code.

12. In a telephone system, a calling station, a code registering and impulse sending mechanism individual to said station, a plurality of serially related switches, an impulse device at said station, means for operating said impulse device to transmit trains of impulses tosaid serially related switches for directively extending a connection to a called station under control of said calling station,

means for operating said impulse device to transmit a code series of impulses to said register mechanism without actuating said serially related switches, automatic means including said impulse sending mechanism operable subsequently for actuating said serially related switches to extend a connection to a called station denoted by said code, and means for transmitting a signal to said calling station during the actuation of each of said serially related switches denoting the numeric value of each of the trains of impulses transmitted thereto.

13. In a telephone system, a calhng station, a central exchange code registering mechanism individualthereto, a plurality of serially related switches, a control device at said station, means for operating said device to actuate saidserially related switches for extending a connection to a called station under control of said calling station, means for operating said device in accordance with a certain code to actuate said register mechanism to the exclusion of said serially related switches, and automatic means operable subsequently for actuating said serially related switches to extend a connection to a called line denoted by said code.

14. In a telephone system, a calling station, a central exchange code registering mechanism individual thereto, a plurality of serially related switches, a control device at said station, means for operating said device to actuate said serially related switches for extending a connection to a called station under control of said calling station, means for operating said device in accordance with a certain code to actuate said register mechanism to the exclusion of said serially related switches, automatic means operable subsequently for actuating said serially related switches under control of said register mechanism to extenda connection to a called line denoted by said code, and means for transmitting a signal to the calling station during the actuation of said serially related switches denoting the numeric value of the setting-of each switch.

15. In a telephone system, a calling station provided with an impulse transmitting device, a centrally located repeater and register mechanism individual to said station, a plurality of serially related switches accessible to said repeater, means in said repeater responsive to the transmission of a single series of impulses for setting said register mechanism in accordance with a certain code corresponding to said impulse series, and automatic means for subsequently transmitting a plurality of series of impulses to said serially related switches for operating the same to extend a connection to a called line under control of said mechanism.

16. In a telephone system, a calling station provided with a control device, a central oilice control mechanism individual to said station, a plurality of serially related central ofiice switches accessible to said mechanism, means in said mechanism responsive to the operation of said control device for setting said mechanism in accordance with a certain code corresponding to said operation, and automatic means for subsequently actuatin said serially related switches to extend a connection to a called line under control of said mechanism.

- 17. In a tele hone system, a calling station, central oflice code register and. sender mechanism individual to said station, serially related switches, means at the calling station for directly operating said switches to extenda connection to a called station, and means at the calling station for directly operating said mechanism to cause said sender mechanism to operate said switches to extend a connection to a called station.

18. In a telephone system, a calling station, central oflice code register and sender mechanism individual thereto, serially related switches, means at said station for directively setting said register mechanism in accordance with a certain code, and means in said sender mechanism controlled by said register mechanism for actuating said switches to extend a connection to a called station.

19. In a telephone system, a calling station, central oilicc code register and sender mechanism individual thereto, serially related switches, means at said station for directively setting said register mechanism in accordance with a certain code, means in said sender mechanism controlled by said register mechanism for actuating said switches to extend a connection to a called station, and means for transmitting a signal to said calling station during the actuation of each of said switches, denoting the numeric value of the setting of each switch.

20. In a telephone system, a calling station a central office control mechanism individual to said station and including a plurality of register switches, means at said station for actuating said register switches in accordance with a certain code, sender mechanism, serially related switches accessible to said sender mechanism, and means for actuating said sender mechanism under control of said register switches to operate said serially related switches to extend a connection to a called station.

21. In a telephone system, a calling line, means at the station on said line for optionall transmitting one or a plurality of impu se series over the calling line for controlling automatic switches to extend a connection to a called line, and means at the exchange responsive to a single series of impulses to transmit a plurality of impulse series to such automatic switches to extend a connection to 9. called line.

22. In a telephone system, a calling line, a series of automatic switches responsive to a plurality of series of impulses to extend a connection to specific called lines, subscriber controlled means for optionally transmitting one or a plurality of series of impulses over the calling line to extend and complete such connections, and translating and sending equipment at the exchange for translating a single impulsevseries into a plurality of impulse series to operate said switches for the purpose set forth.

23. In a telephone system, a calling line, automatic switches for extending connections to desired called lines to control cir- 0 cuits for said switches each includin a talking conductor of said line and subscri er controlled means for utilizing either control circuit to operate said switches for the purpose set forth.

24. In a telephone system, a calling line, subscriber controlled switches at the exchange responsive to a plurality of series of impulses to complete connections to called lines, and means including a talking conduc- K) tor of said calling line whereby 'a calling subscriber can optionally cause such impulses to be transmitted from the calling line direct or from the exchange.

25. In a telephone system, a calling line,

5 automatic switches for extending connections to called lines, impulse sending equipment in the immediate vicinity of said switches, and

subscriber controlled means for transmitting a plurality of series of impulses over the calling line to operate said switches for the purpose set forth or to transmit impulses of a different character over the calling line to cause said impulse sending equipment to transmit impulses such as referred to in the 35 first instance to said switches.

In witness whereof, I hereunto subscribe my name this 8th day of November, A. D.

JOHN WIGKS. 

